简介:2012年10月间,美国EchoStar通信公司向劳拉空间系统公司(SS/L)订购了一颗新一代电视直播卫星EchoStar18,该卫星未来升空后将提供给美国第二大的直播卫星电视运营商DISH网络公司使用;欧洲两大卫星运营商SES和Eutelsat公司也分别订购了两颗新一代通信卫星SES9及Eutelsat8WestB,其中SES9卫星升空后将服务于亚洲及印度洋区域,而Eutelsat8WestB将为中东和北非地区增加新的广播资源。在此期间,欧洲阿丽亚娜空间公司(Arianespace)获得了两颗印度卫星GSAT7和Insat3D的发射服务合同。
简介:Withrapiddevelopmentcommunicationsystem,highsignaltonoiseratio(SNR)systemisrequired.Inhighfrequencybandwidth,highloss,lowQinductorsandhighnoisefigureisasignificantchallengewithon-chipmonolithicmicrowaveintegratedcircuits(MMICs).Toovercomethisproblem,highQ,lowlosstransmissionlinecharacteristicswasanalyzed.Comparedwiththesameinductorvalueofthelumpedcomponentandthetransmissionline,ithasahigherQvalueandlowerlossperformanceinhighfrequency,anda2-stagecommon-sourcelownoiseamplifier(LNA)waspresented,whichemployssourceinductorfeedbacktechnologyandhighQlowlosstransmissionlinematchingnetworktechniquewithover17.6dBsmallsignalgainand1.1dBnoisefigurein15GHz–18GHz.TheLNAwasfabricatedbyWINsemiconductorscompany0.15μmgalliumarsenide(GaAs)Phighelectronmobilitytransistor(P-HEMT)process.Thetotalcurrentis15mA,whiletheDCpowerconsumptionisonly45mW.